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The purpose of this paper is to give a brief introduction of helical spring locked washer along with extensive literatures survey on role of helical spring locked washer in bolted joint analysis. It is very small component of bolted joint assembly, but it play vital role in holding the assembly components together. Helical shape of it produces spring effect in the assembly which is used for keeping the assembly in tension and that is lock the assembly under dynamic loading due to vibrations to avoid the accident.

The critical literatures survey identifies role of helical spring locked washer in different areas such as design optimization, mechanism of loosening-resistant components, bolted joint analysis, finite element-based modeling, analysis and simulation. The related literatures show contribution of helical spring washers in evaluation of anti-loosening performance of assemblies as compare to other types of washers.

It proposed that design optimization of helical spring locked washer is needed as it improves the performance in the form of load-deflection characteristics, load bearing capacity and provides the best locking force for optimize functionality.

The originality or value of this paper is to finding research gaps in literatures by dividing literatures into seven different research areas and concentrating the only on role of helical spring locked washer in bolted joint analysis.

The helical spring lock washer (HSLW) is a part of nut bolt joint assembly used in different industries like automobile, aerospace, mechanical, chemical, electrical, electronics, etc. It works as a part of temporary joint and plays important role in loosening behavior of assembly under dynamic (vibrations) conditions. Thus, the purpose of this paper is to investigate the performance of HSLW under different controlled operating conditions in order to satisfy its functional requirement.

In the present investigation, a novel test rig is designed and developed to determine the load-deflection characteristics of HSLWs. The test rig facilitates the controlled linear displacement of the HSLW with predetermined angular rotation of the handle gives the corresponding reaction load on the display. Additionally, the repeatability and reproducibility of the test rig was carried out.

The newly designed and developed test rig is capable enough to differentiate the load-deflection characteristics during compressive loading and unloading of HSLWs. Additionally, the loss of strain energy can be determined from the load-deflection characteristics of HSLW.

The present test rig is designed and developed to investigate the load-deflection characteristics under compressive loading and unloading of HSLW. The test rig has least count of 0.4905 N for load measurement and 0.01389 mm for linear displacement.

The purpose of this paper is to explore the applications and technological details of common components – rings and springs.

The characteristics and applications of compression springs and then extension springs are investigated, and various finishing techniques are reported. Rings ranging from flat washers to snap‐rings, push‐on rings and Smalley rings are presented.

The humble spring may be surprisingly high‐tech, with applications in fuel injection, pacemakers and insulin delivery systems. Springs fulfill shock absorption duties as well as securing tasks, and can pre‐load fixtures to withstand thermal expansion and vibration. Retaining rings are used in heavy duty lifting gear and wind turbines, whilst simple washers elegantly combine wear protection with insulation in securing circuit boards.

The paper highlights the continuing development and surprising strengths of some simple components.

SINCE so little information has been made available in this country with regard to Russian aero‐engines, it was thought worth‐while to attempt to compile a description of this engine, although it was first produced at least fifteen years ago. This description is necessarily incomplete and to some extent disjointed because most of it is based on references contained in the book Aero‐Engines—Design and Detail Calculations, edited by A. E. Zaikin, of the Joukowsky Military Aviation Academy of Kiev, and published in 1941 by the State Publishing House of the Defence Industry. This book was not intended to describe any one engine but rather, to indicate the merits and demerits of various components of many engines including English, American, French and German products. It is known that most of the aero‐engines produced in Russia are of foreign origin and for this reason it was assumed that interest would be taken in the AM.34 which does appear to be of Russian design.

THE following description of the fuel supply systems of the BMW 132K and 132N, “Bramo” Fafnir 323 P‐1 and BMW 801 air‐cooled radial engines is based on the following reports supplied by the Ministry of Aircraft Production.

THIS note describes the arrangement of the engine cowlings on certain types of German aircraft. In each case the cowling is attached directly to the engine and not to the fuselage so that the engine can be removed complete with its cowling. The arrangement enables the engine to vibrate on its rubber mountings relative to the fuselage without any risk of distortion of the cowling. These cowlings all appear to be designed to facilitate rapid removal and replacement and to have the cleanest possible form when assembled.

BMW 801A/1 The engine is a radial, air‐cooled, fourteen‐cylindcr, double‐bank motor of 42 litres capacity, 6–5/1 compression ratio and 156 mm. bore and stroke.

IN a recent issue of AIRCRAFT ENGINEERING there appeared a very brief description, and some illustrations of the Junkers airscrew which aroused considerable interest. Since then we have had the opportunity, through the courtesy of Rotol Airscrews Limited, of inspecting an example of this unit.

The purpose of this paper is that the modular mobile robots reformed the multimachine joint mode to achieve obstacle-crossing, climbing and other multifunctional inspection in unstructured environment under the connection of the cone–hole docking mechanism.

An arc-shaped docking cone head with a posture-maintaining spring and two arc-shaped connecting rods that formed a ring round hole were designed to achieve large tolerance docking. Before active locking, the coordination between structures was used to achieve passive locking, which mitigated the docking impact of modular robots in unstructured environment. Using the locking ring composed of the two arc-shaped connecting rods, open-loop and closed-loop motion characteristics were obtained through the mutual motion of the connecting rod and the sliding block to achieve active locking, which not only ensured high precision docking, but also achieved super docking stability.

The cone–hole docking mechanism had the docking tolerance performance of position deviation of 6mm and pitch deviation of 8° to achieve docking of six degrees of freedom (6-DOF), which had a load capacity of 230 N to achieve super docking stability. Under the connection of the cone–hole docking mechanism, the modular mobile robots reformed the multimachine joint mode to achieve obstacle-crossing, climbing and other multifunctional inspection in unstructured environment.

Based on mechanical analysis of universal models, a cone–hole docking mechanism combining active and passive functions, six-dimensional constraints could be implemented, was proposed in this paper. The characteristics of the posture-maintaining spring in the cone docking head and the compression spring at the two ends of two arc-shaped connecting rods were used to achieve docking with large tolerance. Passive locking and active locking modules were designed, mitigating impact load and the locking did not require power to maintain, which not only ensured high precision docking, but also achieved super docking stability.

Chester Street, Aston, Birmingham, 6. The ‘Donald’ Patent Barrel Lifter Truck and Stand, the three‐in‐one appliance. Barrels up to 7 cwts. lifted and transported by one man. ‘Donald’ Patent Barrel Lifter Stands for Oil Stores.